tests freeze on julia 1.4

[AshtonSBradley]

tests freeze here

...
  [44cfe95a] Pkg 
  [de0858da] Printf 
  [3fa0cd96] REPL 
  [9a3f8284] Random 
  [ea8e919c] SHA 
  [9e88b42a] Serialization 
  [6462fe0b] Sockets 
  [2f01184e] SparseArrays 
  [10745b16] Statistics 
  [8dfed614] Test 
  [cf7118a7] UUIDs 
  [4ec0a83e] Unicode 
Test Summary:     | Pass  Total
Special functions |   19     19
Test Summary:       | Pass  Total
Chebyshev transform |  250    250
Test Summary:                         | Pass  Total
Fejér and Clenshaw--Curtis quadrature |    9      9

[AshtonSBradley]

julia> versioninfo()
Julia Version 1.4.0
Commit b8e9a9ecc6 (2020-03-21 16:36 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin18.6.0)
  CPU: Intel(R) Core(TM) i5-8259U CPU @ 2.30GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-8.0.1 (ORCJIT, skylake)
Environment:
  JULIA_NUM_THREADS = 4